Project Summary: My career objective is to run a molecular virology laboratory at a research and education institute initially focused on elucidating the biochemical mechanisms required for influenza viral replication. The proposed research aims to define the roles of viral and cellular proteins required for influenza viral RNA synthesis and processing. Experiments are designed to probe function of mutant viral proteins and identify virus-host interactions involved in influenza virus propagation. Specific Aim 1 will examine the RNA synthesis and processing activities of mutant influenza proteins, both in vitro and in vivo, to define the role of viral - viral and viral - host protein interactions essential to viral propagation. Experiments will probe the role of influenza nucleocapsid protein (NP) and RNA dependent RNA polymerase (RdRP) contacts, and two identified viral - host interactions;the influenza RdRP with the C-terminal domain (CTD) of cellular RNA polymerase II, and influenza NP with host cellular splicing and export factor UAP56. Specific Aim 2 will identify host splicing and nuclear export factors hijacked by influenza viral mRNAs. Known cellular export pathways will be examined for their function during influenza virus infection. To discover novel cellular nuclear export pathways, cis regions within the viral mRNAs that are required for viral mRNA export will be defined through mutagenesis screening. The discovered RNA element(s) will then be utilized to identify cellular proteins which specifically bind the viral RNA. Viral mRNA splicing and export is an area poorly understood for influenza viruses. The proposed research will provide assays to screen and discover compounds which inhibit influenza virus infection and may lay foundation for development of antiviral therapies. Further, this research has potential to discover novel cellular RNA processing and nuclear export pathways. Relevance: Influenza is a pressing health issue for humans. The best line of defense for a rapidly emerging highly pathogenic virus is anti-viral medications, although resistance makes the search for new anti-viral targets a constant struggle. The proposed research aims to understand molecular mechanisms required for influenza viral infection with the intent to lay the foundation for development of novel anti-viral therapies.